Polymers and copolymers of nu-pyrimidyl amides of alkene-1, 2-dioic acids



.i atented Sept. 2, 1953 POLYMERS ANT) COPGLYMERS F N-PYRM- IDYL AREDES 0F ALKENE-LZ-DIQIC ACIDS Gaetano F. DAlelio, Pittsburgh, Pa., assignor to Koppers Company, Inc., a corporation of Delaware No Drawing. Application June 26, 1953 Serial No. 364,508

15 Claims. (Cl. 266-78) This invention relates to new monomers and to new polymeric materials derived therefrom and is particularly directed to the polymerization products obtained by polymerizing a mass comprising as a new monomer a pyrimidyl amide of an ethylenic alpha, beta-dicarboxylic acid hereinafter referred to as a polymerizable ethenedioic acid and a copolymerizable compound especially acrylonitrile. The invention also relates to compositions of these polymerization products adapted to the formation of shaped articles, in many cases to molecularly oriented shaped articles, particularly to fibers, threads, bristles, mono-filaments, etc., hereinafter referred to as fibers, and other shaped articles such as films and the like, which articles show improved dyeing properties.

It has been known for some time that certain copolymers of acrylonitrile may be adapted to the preparation of shaped articles, such as, films, fibers, foils, tubes, etc. Some of these copolymers have been regarded as capable of being cold-drawn to produce structures molecularly oriented along the fiber axis. Cold-drawing may be defined as the stretching of a polymeric material at a temperature below the melting point of the material to give a molecularly oriented structure.

The resistance of acrylonitrile polymers to dyes of all types has presented serious dyeing problems, especially in the development of synthetic fibers from these polymers. In fact, in order to dye polyacrylonitrile one commercial process resorts to the use of high pressures with water solutions or organic dispersions of dyes. It has been proposed that improvement in dye susceptibility can be obtained by the use of itaconic acid in small amounts as copolymerizing monomer in the preparation of acrylonitrile polymers. However, the polymer products obtained thereby have a tendency to crosslink upon standing at temperatures of at least about 70-80 C. or upon spinning from hot solutions. Such cross-linking causes spoliation of material by gelation during storage, embrittlement of fibers, fouling of spinning jets, and other production difliculties.

In accordance with the present invention it has now been found that crosslinking is avoided and that improvements in dyeing properties of acrylonitrile polymers are obtained by the polymerization of monomeric masses comprising acrylonitrile and N-pyrimidyl amide of a polymerizable ethenedioic acid with or without other copolymerizable ethylenic compounds. It has been found further that in addition to the fact that the N-pyiimidyl amides of polymerizable ethenedioic 'acids yield particularly valuble copolymers with acrylonitrile, they can also be used effectively to form copolymers with other types of copolymerizable ethylenic compounds having a CH =C group Thus it has been found that valuable polymerization products may be prepared in accordance with the invention by polymerizing a monomeric mass comprising an N-pyrimidyl amide of a polymerizable ethenedioic acid and a polymerizable compound such as acrylonitrile and the other polymerizable ethylenic compounds listed hereinafter.

The amides of this invention are formed by reacting an amide-forming pyrimidine, that is, an aminopyrimidine having replaceable N-hydrogen with a polymerizable ethenedioic acid, or the anhyrides or acid chlorides of these acids. The readily polymerizable ethenedioic acids include maleic acid, fumaric acid, citraconic acid, and mesaconic acid. These acids may be represented by the formula in which R is either hydrogen or the methyl radical. (The formulas herein are not intended to distinguish between cis and trans forms.) Since the ethenedioic acids are dibasic, one of the carboxyl groups can be esterified either before or after amidation. Another amide group similarly can be introduced either before or after the amidation. The amidation can also be carried to the diamide stage. When it is carried to the mono-stage only, the remaining carboxyl group can be esterified or amidated (with ammonia or another amine as desired).

For reasons of economy and ease of preparation the methyl or ethyl ester of N-(2,6-dimethyl-4-pyrimidyl) amide acid is usually preferred when an ester is used and has the formula in which R is either the methyl or ethyl radical. These esters are prepared simply by refluxing methanol or ethanol with the proper ethenedioic anhydride to form the acid ester and the acid ester formed is then converted to the acid chloride by refluxing with thionyl chloride and the acid chloride formed is thereafter reacted with 4- amino-2,6-dimethyl pyrimidine to produce the desired ester, that is, the methyl or ethyl ester of N-(2,6-dimethyl- 4-pyrirnidyl) amide acid. The amide-acid itself is conveniently prepared by reacting the proper anhydride or the acid chloride with 4-amino-2,6-dimethyl pyrimidine. The acid chloride and anhydride are sufliciently reactive to form the above esters or amides merely upon the mixing at room temperature. In some cases where the acid chloride or anhydride is not as reactive or in order to get more complete reaction, gentle heating may be advantageous. As an alternate synthesis of the esteramide, the amide acid can be readily converted to a sodium or potassium salt and esterified with dimethyl or diethyl sulfate to the corresponding ester.

The N-pyrimidyl amides of polymerizable ethenedioic acids are represented by the formula a heterocyclic group; R is hydrogen or the methyl radical; and Z is the group in which R is selected from the class consisting of hydrogen and alkyl groups, such as, methyl, ethyl, isopropyl, n-butyl, sec-butyl, amyl, heXyl, decyl, and the like, preferably containing not more than three carbon atoms and Pyrm is a pyrimidine nucleus. The pyrimidine nucleus can be substituted or unsubstituted as in the case V acetoxy-cyclohexyl,

2,850,484 r a .7 f

of 4-amino-pyrimidine, 4-amino-2,o-dimethyl-pyrimidine, 4-amino-2,6-diethyl-5 methyl-pyrimidine and like amino pyrimidines. Other suitable pyrimidines and methods for their manufacture are given by Larchar, U. S. Patent 2,540,826, and Brown, [Sow Chem. Ind: 69, 353+ (1950). If substituted it is preferredthat the substituents shall be alkyl groups as listed above, but preferably containing not more than a total of five carbon atoms.

. Whe'n'the amides used in the practice ofthe invention'co'ntain an ester group or an amide group otherthan group Z the radical R can be methyL ethyLpi-opyl, iso-' propyl, n-butyl, sec-butyl, amyl, hexyl, decyl, chloromethyl, chloroethyl, cyclohexyl, f methyl-cyclopentyl, propyl-cyclopentyl, amyl-cyclopentyl, methyl-cyclohexyl, dimethyl-cyclohexyhj chlorocyclohexyl, phenyl, chlorophenyl, xenyl, naphthyl, tolyl, chlorotolyl, xylyl, ethylphenyl, propyl-phenyl, isopropyl-phenyl, benzyl, chlorobenzyl, phenethyl phenyl-propyl, phenyl-butyl, 'acetoxyethyl, chlorophenoxy -ethyl, acetoxy-propyl, acetoxy-isopropyl, acetoxy-phenyl, acetoxy-benzyl, acetoxy-tolyl, methoxy-propyl, ethoxy-propyl, methoxy-phenyl, methoxy-benzyl;methoxy-tolyl, meth oxy-cyclohexyl, etc. or part of a heterocyclic amino group,

such as, the piperidyl, piperazino and morphoiino' .groups. 7

. The proportions of the amide .in the polymerization products of the invention can vary -over a wide range,

ranging from equimolar proportions of amide down to very small amounts of amide such as can be employed in acrylonitrile polymers to impart dye susceptibility thereto.' Although even smaller amounts are somewhat effective, theimprovement in susceptibility of acrylonitrile copolymers'to' dyes becomes particularly noticeable when the amide content of 'the copolymeri fabout 0.1 percent and the susceptibility increases as the amount of percent; Within these proportions acrylonitrile copolyfmers of the inventionshow great afiinityltoward many dyes especially basic, acidic, vat, and cellulose acetate dyes.

In addition to the improvements efiected'in the result- In such cases the concentra tion of amide can range up to of approaching 50 mole ing copolymers, the use of N-pyrimidyl amides of polymerizable 'ethenedioic acids has certain other advantages over' the use .of the corresponding acids. :"For example,

the amides are more soluble in acrylonitrile than the.

Therefore it is generally easier to'get complete acids. copolymerization of the amide'with' acrylonitrile in solution, emulsion and suspension p'olymerizatious. Still further advantages accrue from the presence of these amides.

Thus when non-esterified mono-amides are used the copolymers of the invention show high susceptibility to basic dyes. 7

The acylonitrile copolymrs'discussed herein are soluble in N,N-dimethyl acetamide.(DMA), N,N-dimethyl formarnide (DMF), butyrolactone,yethylene carbonate, N,N-dimethyl methyl urethane of the formula V V (cH hNCQOCl-l 1 V ethylene carbamate, N-methyl-2 -pyr rolidone; and a num: ber of similar solvents, used alone orin conjunction with N,N-dimethyl cyanarr'iide, N,N-di'rf1ethyl cyano-acetamide, N,N-dimethyl methoxy-acetamide; methylene 'di 'nitrile, methylene dithiocyanate, 'formyl caprolactam, V

formyl morpholine, tetramethylene sulfone;'etc. Nitro alkanes, such as nitromethane, maybe used as solvents for such'copolymers having no more than about 85 per-.

cent acrylouitrile, providing the 'comonomers' used in 9 a ls greater en wzhq'a ia fa ts-i a preparing such copolymers do not have substituent groups i i V V I v 4 cyano groups in acrylonitrile. ent invention which have high proportions'of monomers. of relatively low secondary-yalence bonding strength, uch as, vinyl chloride, may often be dissolved in acetone or mixtures of acetone and solvents of the above types.

v This invention will be more fully described by the following examples which illustrate methods of prac'-- ticing the invention. 'In these examples and throughout .the specification, parts and percentages are intended to mean parts by weight and percentages by weight.-

7 Example I 24.4 grams (0.2 mol) 4-amino-2,6-dimethyl pyrimidine:

is admixed with approximately ml. diethyl ether and Ultimate analyses for carbon, hydrogenand nitrogenand molecular weight determinations on the product give:

results which are in close agreement with the theoretical values for N-(2,6-dimethyl 4-pyrimidyl) maleic acid monoamide.

Substitution of equivalent. quantities of polymerizable ethenedioic acid anhydrides or amino-pyrimidines," respectively, in the foregoing procedure for the maleic anhydride and -4-amino-2,6-dimethyl pyrimidine there used yields the various mono-pyrimidyl amides of the ethenedioic acids of this invention which are characterized by ultimate analysesand molecular weight determinations as in the'foregoing procedure...

Example I] V i 4. 4 .0 igrams (0.2 mol) N-2,6-dimethyl-4-pyrimidyl) maleic acid monoamide (prepared as in Example I) is dissolved in a minimum amount of water and 8.0 grams (0.2 mol). sodium hydroxide added slowly to form the sodium salt. The water is evaporated and the residue is admixed with approximately. 150 ml. diethyl ether. .There is added slowly and with stirring 25.0 grams (0.2 mol) dimethylsulfate, .Theether is evaporated and the residue recrystallizedfrom absolute ethanol. There is obtaineddthe methyl ester of the mono-amide of the ethenedioic acid. s

Ultimate'analyses for carbon, hydrogen and nitrogen andmolecular Weight determinations on the product give results which are'in close agreementwith the theoretical ethenedioic acid.

Substitution of the various mono-amidesof Example I or diethyl sulfate respectively in the foregoing procedure for the N-(2,6-dimethyl-4-pyrimidyl)maleic acid mono-amide and dimethyl sulfate there used yields the various methyl and ethylesters of the, mono-amides of ethenedioic acids of this inventionswhich are characterized by ultimate, analysesand molecular weight determination as in theforegoing procedure. A, v

Example 111 44.0 grams (0.2 mol) N-(2,6-dimethyl-4-pyrimidyl) maleic acid mono-amideis admixed with approximately 150 ml. diethyl ether and 29.7 grams (0.25 mol) thionyl chloride and themixture refluxed for approximately /2 hour. acid chloride.

This acid chloride to a mixture of 10.0 grams (0.2 mol) dimethyl amine and 150 ml; diethyl ether in a flask equipped with a reflux condenser. After the addition of the acidchloride 1 oxide to remove thechlor ide ion. The mixture is filtered and the filtrate evaporated to dryness, The residue is Copolymers of the pres- The ether isevaporated'and there is obtained the is added slowly and with stirring 3 recrystallized from absolute ethanol. There is obtained N-dimethyl-N-(2,6 dimethyl 4 pyrimidyl)ethenedioic aicd diamide.

- procedure.

Example IV 47.7 grams (0.2 mol) of the acid chloride of Example 111 is added slowly and with stirring to a mixture of 24.4 grams (0.2 mol) 4-amino-2,6-dimethyl pyrimidine and 150 ml. diethyl ether in a fi-ask equipped with a refiux condenser. After addition of the acid chloride, the mixture is refluxed for approximately hour and the ether is then evaporated. The residue is dissolved in Water and shaken with 29.0 grams (0.125 mol) silver oxide to remove the chloride ion. The mixture is filtered and the filtrate evaporated to dryness. The residue is recrystallized from absolute ethanol. There is obtained N,N'- (2,6-dimethyl-4-pyrimidyl) ethenedioic acid diamide.

Ultimate analyses for carbon, hydrogen and nitrogen and molecular weight determinations give results which are in close agreement with the theoretical values for N,-N 2,6-dimethyl-4-pyrimidy1) ethenedioic acid diamide.

Substitution of equivalent quantities of the various acid chlorides obtained in Example 111 or various amino pyrimidines in the foregoing procedure for the particular acid chloride and amino pyrimidine there used yields the various diamides of ethenedioic acids of this invention which are characterized by ultimate analyses and molecular Weight determinations as in the foregoing procedure.

Example V Five polymers of acrylonitrile are prepared from the following monomer compositions The 100 parts of monomer or monomer mixture is, in each case, slowly added over a period of less than an hour to 7501,000 parts of distilled Water at 3050 C. containing dissolved therein one part of ammonium persulfate, 0.6 to 1.5 parts of sodium bisulfite and 0.5 parts of v sodium dodecyl-benzene sulfonate. The reaction is continued for 2-6 hours, at which time a yield of about 90 percent solid polymer is precipitated. The resulting polymers have molecular weight over 10,000. Each polymer is dissolved in N,N-dimethyl acetamide or butyrolactone and a film cast from each solution.

A water solution of methylene blue dye (a basic dye) is prepared by making a paste of the dye and then diluting to a one percent by Weight dye solution. This dye solution is kept boiling for one hour while the aforementioned films are immersed therein for one hour. The dyed films are then removed and separately subjected to washing with boiling water for one hour, the boiling water being changed frequently to remove the desorbed dye. The unmodified polyacrylonitrile film when treated 5 in this manner showns only a light tint, whereas the mono- N-(2,6-dimethyl-4-pyrimidyl) maleic amide-acid copolymers are dyed a deep and dense shade. Identical films, cold-drawn and heat-treated, show dyeing characteristics similar to the undrawn films.

Fibers are spun from the same N,N-dimethyl acetamide or butyrolactone solutions either by dry spinning or by wet spinning, into glycerine baths. The fibers are substantially freed from solvent and dried. After cold-drawing the dried fibers 600-900 percent at 120-145 C. and subsequently heat-treating them at 150 C. for one hour, the fibers are given the same dyeing and washing treatment described above with the same results as for the films a light tint being acquired by the unmodified polyacrylonitrile fibers and a deep and dense color being given to the itaconate copolymer fibers.

instead of N-(2,6-dimethyl-4-pyrimidyl) maleic amideacid, the various N-(pyrimidyl) maleic amide-acids, disclosed above may be used. Also the N-(pyrimidyl) amide-acids of the other polymerizable ethenedioic acids may be used.

Example VI Five polymers of acrylonitrile are prepared from the following monomer compositions Methyl ester of N-(2,6- Polymer Acrylonidlmethyl ltrlle, parts pyrlmidyl) maleic amideacid, parts To 900 parts of water, adjusted to a pH of about three, in a suitable reactor, is added 0.5 to 1 part sodium dodecyl benzene sulfonate, 1.0 parts of ammonium persulfate, 0.5 part of sodium bisulfite, and parts of monomer or monomer mixture. The reactor is then flushed with deoxygenated nitrogen and heated with agitation to 50 C. for 24 hours. Steam is introduced into the reactor to remove uupolymerized monomers from the mixture. A small amount of aluminum sulfate is added to the mixture and the polymer isolated by filtration.

The polymer is then washed with water and with methyl alcohol. A portion of the polymer is dissolved in dimethyl formamide or butyrolactone and a film cast from the solution. The film is washed entirely free of solvent and stretched at a ratio of about 8:1 in a glycerine bath at to C. The film is then washed in water and dyed in a bath containing for each part of film 0.05 part of 1,5 diamino-4,8-dihydroxy-anthraquinone-3-sulfonic acid, 0.03 part sulfuric acid and 50 parts water (50:1 bath-film ratio) at boiling temperature for one hour. The film is then removed and washed with water and scoured for 15 minutes in a 0.4 percent soap solution at 85 C. Whereas the unmodified polyacrylonitrile when treated in this manner has little or no color, all of the copolymers are dyed to a deeper blue shade.

Fibers are spun from the same solutions either by dry spinning, or by Wet spinning. The fibers are substantially freed from solvent and dried. After cold-drawing the dried fibers 600-900 percent at 120l45 C. and subsequently heat-treatin them at C. for one hour, the fibers are given the same dyeing and washing treatment described above with the same results as for the films, a light tint being acquired by the unmodified polyacrylonitrile fibers and a deep and dense color being given to the copolymer fibers. The polymers of this example are also soluble in dimethyl formamide, dimethyl acetamide, tetramethyl urea, butyrolactone, ethylene carbonate, formyl morpholine, etc.

aesoesa Instead of the monomethyl ester amide of the above 7 example, various other esters of \N(2,6-dimethyl-4-pyrimidyl). maleic amide-acid can be used, such as the ethyl, propyl, isopropyl, butyl, isobutyl, tertiary-butyl,

hexyl, tolyl, phenyl, naphthyl, cyclopentyl, cyclohexyl,

benzyl, phenethyl, etc. esters. Likewise the esters of the other N-(pyrimidyl') maleic amide-acids disclosed above can be used. V Example VII 4 Five parts of the copolymer fiber D of Example V is then oxidized in a 0.5 percent sodium dichromate 1.0

percent acetic acid aqueous solution at 70 C. for 30 minutes in a'20:1 bath-fiber ratio[ The dyed fiber is then scoured in a 0.5 percent boiling soap solution. A sample of yarn prepared from the unmodified polyacrylonitrile and dyed'under the same conditions 'ac quired only a light shade of color.

When 1,5 di p anisoylamino -'4,8 dihydroxyanthraquinone 'is used as the vat dye, the copolymer fiber is dyed a strong violet color.

The, procedure After the first 15 minutes of heating, 7 0.25 part of Glaubers salt'is added. The fiber sample polymerization of the following monomer compositions Methyl ester of 7 Acrylo- Vinyl N-(2,6-di.methyl- Oopolymer Polymer nitrile, Chloride, .kpyrimidyl) Soluble inparts parts maleic amideacid, parts 7 92 8 Dhtfl, DMA,

e c. s7 10 3 mgr, DMA,

e c. 82 3 DMF, DMA,

etc. 77 3 NO Me. 57 40 3 NO MB. 37 60 3 Acetone.

Sometimes copolymers D and B, when dissolved in nitromethane may have gelled, partially dissolvedparticles known as fisheyes. In such cases, the solubility can be improved by the addition of small'amounts of materials which are good solvents for acrylonitrilepolymers,such

as butyrolactone, ethylene carbonate, dimethyl forn amide, dimethyl acetamide, tetramethyl urea, etc. In addition, certain materials which are relatively poor solvents for polyacrylonitrile, such as diethyl formamide, diethyl acetamide, diethyl propionamide, etc.,' can be added to improve the solubility. Also, when acetone solutions of copolymer F contain gelled particles, clarification of the solution can be effected by the. addition of nitromethane, diethyl formamide, diethyl acetamide,

etc.

' Dyeing tests of these ,copolymers show improvements in dyeing susceptibility similar to those of Example V. The procedure of this example can also be used with the various other amide-esters set forth above.

Example IX The procedure of Example V is repeated for the Dyeing tests ofthese copolymers show. improvements in dye susceptibility similar toExamplewv. In place of styrene, various styrene derivatives can be used, such as alpha-methyl-styrene; nuclear-substituted chloro-styrenes, i. e., ortho-, meta-, and para-chloro-styreues, di-

chloro-styrenes; for example, the 2,3-, 2,4-, 2,5-, -2,6.-,

3,4-, and 3,5-dichloro-styrenes; trichloro-styrenes; cyanor' styrenes, such, as ortho-, meta-, and para-cyanO-styrenes, dicyano-styrenes, nuclear-substituted alkyl-styrenes, such as monoand di-methyl-styrenes, mono and di-ethylstyrenes, monoand di-isopropyl-styrenes, aryl-substi: tuted styrenes, i. e., para-phenyl-styrene, etc.; cycloaliphatic-substituted styrenes, such as para-cyclohexyl-styrene; fiuoro styrenes, suchas ortho-, metar, para-fluorostyrene, ,difiuoro-styrenes, 'etc.; trifiuoro-methyl-styrenes, .such as ortho-,' meta-,sand para-trifluoromethyl-styrenes, di-(trifiuoromethyl)-styrenes, and various other. styrenes 'or mixtures of any number'of these with eachother or withstyrene.

The procedure ofthis example can also be used with the various other :amide-estersset forth above.

- v Example X Y The procedure of Example V is repeated for the polymerization ofthe'following monomer compositions Methyl esterol' e Acrylovinylidene N -(2,6-diethyl- Copolymer Polymer nitrile, Chloride, 5-methyl-4-py- Soluble lnparts parts rimidyl) maleic I amide-acid,parts A- 85 -5 1 10 DMF,DMA;

1 etc. B 65 'f 25 10 DLtEF, DMA,

1 w w ec.' C 45. I '45 a 10 DMF, DMA, i z etc I) 25 65' 1 l0 .DLIF, DMA,

. ec- 'E 5 85 1O DMF,DMA',

- etc. 7

40 With the above vinylidene chloride copolymers and similar copolymers having a total of acrylonitrileand vinylidene chloride of at least 85 percent in the'polymer molecules, only the moreactive" solvents, such as butyrolactone ethylene carbonate, N,N-dimethyl acetamide,

N,N-dimethyl formamide, ;:N,N,N',N'-tetramethyl urea, etc., can be used as solvents. ,The above copolymers dye more readily and thoroughly than similar copolymers containing "no N-(pyrimidyl) 'maleic. acid amide;

p The procedure of this example can also be used with the various other amide-esters set forth above.

' Ethyl'ester of Acrylonitrile, Vinylidene Vinyl Chlo- N-(2,6-dimethyl- Polymer parts Chloride, ride, parts 4-pyrimidyl) parts maleic amideacid, parts susceptibility similar to the copolymers of'Example 'V. The procedure of this example can also be used with the various other amide-esters set' forth above.

the acrylonitrile, copolymers of the maleic amide, such as polymers D and E of Example VI can be used as modifiers for the unmodified homopoly'mers and copolymers of acrylonitrile. 'For example, polymer E of The dyeing tests; of the copolymer products" show dye Example XII' 7 V p 7 Instead of copolymerizing the maleic acid amides with a. i

Example VI, which consists of 80 parts of acrylonitrile and 20 parts of methyl ester of N-(2,6-dimethyl-4-pyrimidyl) maleic amide-acid, excellent compatibility With homopolymers of acrylonitrile. In many cases, it is desirable to use the copolymers of the N-pyrimidyl maleic acid amides, which have even a higher ratio of the maleic acid amide, as for example, as high as equal molar ratios of the maleic acid amide copolymerized with acrylonitrile or methacrylonitrile. Suitably from about 10 to 15 to about 70 percent of amide can be used. The overall amounts of amide required to improve the dyeability generally corresponds to the amounts indicated above for copolymers in which the main body of the acrylonitrile polymers contain the amide copolymerized directly therein, that is, for at least about 0.1 percent to advantageously 5 percent or even up to 15 percent amide in the ultimate polymer mixture. The copolymers of maleic amides with other monomers are also satisfactory such as, for example, copolymers of styrene, methyl acrylate, ethyl methacrylate, alpha-methyl-styrene, etc., and these copolymers can be prepared substantially in accordance with the procedure of Example V. A solution of these copolymers is prepared in dimethyl formamide and added to a dimethyl formamide solution of polyacrylonitrile, so that a composition containing 90 parts combined acrylonitrile and other monomer units and about parts of the amide units is obtained. The solution as heated to 130 C. after which the solution is filtered. Films and fibers prepared from this mixture are dyed in accordance with the process of Example VII and satisfactorily dyed, shaped articles are obtained. The unmodified polyacrylonitrile without the addition of these maleic acid amides showed little or no dye retention.

When it is desired to modify an acrylonitrile copolymer such as the copolymer of acrylonitrile and styrene or the copolymers of acrylonitrile and other copolymerizable ethylenic compounds, it is usually desirable to use as modifiers copolymers containing at least one structural unit present in the acrylonitrile copolymer. Thus as there are present in the acrylonitrile copolymer, structural units derived from the acrylonitrile and styrene, it is desirable to have present in the modifying copolymer structural units derived from styrene and/ or acrylonitrile, advantageously both, in addition to those derived from the amide. By thus including in the modifying copolymers structural units of the same type as the structural units of the copolymer to be modified, greater compatibility between the acrylonitrile copolymer to be modified and the modifying copolymer is obtained and the two are more readily soluble in the mutual solvent and will more readily mix into homogeneous polymer mixtures.

The di-N-pyrimidyl maleic amides of the structure RCCO-NR"Pyrm HC-C ON RPyrm in which R, R, and Pyrm are as described above can be used instead of the mono amide in the practice of this invention.

The polymerization products of the present invention have in the polymer molecule a plurality of repeating units of the formula in which Y, Z, and R, are as indicated above and will contain additional repeating units of the formula when the amide is copolymerized with acrylonitrile.

In addition, the copolymers can contain any number of repeating units of the type obtained by the copolymerization of the amides of the invention or a mixture of acrylonitrile and the amide with one or more copolymerizable ethylenic compounds, such as, for example,

vinylidene chloride, vinyl chloride, styrene, alpha-methylstyrene and methacrylonitrile. When the polymerization mass contain, in addition to the pyrimidyl maleic amides, a polymerizable monomer having a CH =C group in an amount such that the latter monomer is present to an extent of at least 50 mol percent of the overall monomer content, then monomers such as fumaronitrile, betacyano-acrylamide and methyl beta-cyano-acrylate can also be present in the polymerization mixture.

As previously indicated, the solvent resistance of such copolymers as contain one or more monomer units in addition to those formed by the acrylonitrile and the amides of the invention is affected by the type and proportion of copolymerizing monomer or monomers used to replace part of the acrylonitrile. For example, copolymers containing small amounts of the amide units can contain various proportions of such monomer units as obtained from vinylidene chloride, methacrylonitrile, 'fumaronitrile, and 'beta-cyanoacrylamide without considerable reduction in solvent resistance. Replacement of acrylonitrile units in the copolymers by vinyl chloride, styrene alpha-methyl-styrene units result in copolymers of lowered solvent resistance, the amount of such lowering in resistance in each case depending on the amount substituted. In addition to the solvent resistance, certain other physical properties of the copolymers are affected by the presence of these additional units in the copolymers. The amount and character of the changes in physical properties of these copolymers depend again on the type and proportion of copolymerizing monomer or monomers used. For example, the tensile strength of an acrylonitrile-amide type copolyrner will decrease much more when a monomer having relatively weak secondary bonding forces, such as styrene or ethylene is used to replace part of the acrylonitrile than when one or more monomers having relatively strong bonding forces, such as methacrylonitr'ile, fumaronitrile, beta-cyano-acrylamide, methyl beta-cyano-acrylate and vinylidene chloride, is used to replace part or" the acrylonitrile. Moreover, the ability of these copolymers to form molecularly oriented shaped articles depends on the type and amount of the copolymerizing monomer or monomers used to replace acrylonitrile.

Other copolymerizable ethylenic compounds, which can also be present in the polymerizable masses for copolymerization with the amides used in the practice of this invention include one or more of the following: acrylates, e. g. methyl acrylate; methacrylates, e. g. methyl methacrylate; acrylamides; methacrylamides; vinyl esters, such as vinyl acetate; itaconic diesters, such as dimethyl and diethyl itaconates; itaconamide; vinyl halides, such as vinyl fluoride, vinylidene fluoride, tetrafiuoroethylene, trifiuorochloroethylene; vinyl aryls, such as vinyl naphthalenes and the nuclear-substituted styrenes listed in EX- ample IX, etc.

The polymerization products of this invention can be prepared by various polymerization systems, such as emulsion, suspension, mass and solution polymerizations. In addition to the monomers, the polymerizable mass can also contain other materials such as catalysts, e. g. peroxides, such as benzoyl peroxide, naphthyl peroxides, phthalyl peroxide, tertiarybutyl hydro-peroxide, hydrogen peroxide, cyclohexyl hydroperoxide, tertiarybutyl perbenz'oate, etc., azo catalysts, persulfates, such as ammonium persulfate, etc., solvents, suspension or emulsion media, emulsifying agents, suspension agents, plasticizers, lubricants, etc.

For use in the preparation of shaped articles, the polymerization products of this invention have molecular weights preferably of at least about 10,000. l-Iowever, polymerization products of molecular weights less than 10,000 may be used for other purposes, such as impregnants, solvent resistant coatings, etc. The molecular weight of the polymerization products is dependent on the other solvent compositions of these copolymers.

' crystalline regions. 'The intensity or number of these bright spots increases with the degree of orientation or crystallization. Amorphous or non-crystalline materials give X-ray diagrams having very few high lights or bright spots whereas crystalline or oriented materials give definite X-ray diifraction patterns.

to position and spacing which are generally characteristic of the composition of the material being X-rayed. In fibers or films theorientation usually follows the direction of drawing'or stretching so that the orientation is parallel to the fiber axis or a major surface.

Useful fibers can 'be made from the solutions of the copolymers of this invention by dry spinning,. as in the preparation of cellulose acetate fibers, or by wet spinning, as in' the preparation of viscose rayona In wet spinning,

.the solution of copolymer can be spun into a substance which'is a non-solvent for the copolymer, but which is advantageously compatible with the solvent in which the "copolymer is dissolved. For example, water, acetone,

methyl alcohol, carbon disulfide, glycerine, chloroform, carbon tetrachloride, benzene, etc., can be used as a precipitating bath for N,N-dimethyl acetamide, N,N,N',N- tetramethyl urea, butyrolactone, ethylene carbonate, and The extruded fibers, from which substantially all of the solvent has been removed in the spinning step, about 1-10 per- .cent remaining in the shaped article, can then be colddrawn about 100-900 percent, preferably about 300-600 .percent; and the drawn fiber heat-treated, usually at substantially constant length, at about 100-160 C. to effect further crystallization and removal of the remaining solvent. The term heat-treated, as used herein, refers to the application of heat to an object, usually at a controlled temperature and usually by means of the medium surrounding the object.

Many of the acrylonitrile copolymers of this invention can be molecularly oriented, especially if there is no more In these patterns there i are definite relationships of the bright spots with regard The celluloseacetate dyes which areefiectivewiththese polymerization products are mainly amino-anthraquinone derivatives. 7 The basic dyestufls toward which these polymerization products show great. aflinity are preferably those. which contain amide, alkylamido, or ammonium groups, as fNHz, TN(C2H5)a, NHC H N (CH OH, etc. and which may also be :used in the form of their salts, i. e. the hydrochlorides,

sulfates or oxalates. Some of these basic dyesare Methylene Blue, Rhodamine B, 'Indamine Blue, Auramine, Meldolas Blue, Chrysoidine Y, AcridineYellow, Magenta, Crystal Violet, Thiofiavine T, Satfranine and Bismarck Brown. The cellulose acetate dyes' which are effective with thesepolymerization products are mainly .amino-anthraquinone derivatives, basic azo compounds 7 and other basic substances, such as the Duranol, Dispersol, Sericol, etc.,dyestufis. A number of other acidic dyes that can be used are anthranilic acidl-(4sulfophenyl), 3-methyl-5-pyrazolone; 1,5-diamino-4, 8-dihydroxyanthraquinone 3 sulfonic acid; l-amino naphtha lene-4-sulfonic acidalpha-naphthol-4-sulfonic acid; the sodium salt of sulfanilic acid-e aniline Z-benzoyl-amino- '5-naphthol-7-sulfonic acid; the sodium salt of 4,4'- x diaminostilbene-2,2'-di-sulfonic acidl; (phenoD ethylated; l,5-diamino-4,8-dihydroxyanthraquinone-3-sulfonic acid; dye prepared by diazotizing l-aminonaphthalene-4- sulfonic acid and coupled, with alpha-naphthol-4-sulfonic than 15 percent of amide in the copolymer molecule.

This is true when the major portion of the copolymer is acrylonitrile, for example, 85 percent or more acrylonitrile, or when the other copolymerizing monomers used in making such copolymers have substituent groups having secondary-valence bonding forces equal to or greater than exhibited by the cyano group in acrylonitrile. For

example, if such monomers as methacrylonitrile, fumaronitrile, vinylidene chloride, beta-.cyano-acrylamide and methyl beta-cyano-acrylate are used with acrylonitrile and an amide according to the invention, the proportion of acrylonitrile in the copolymers can be much less than 85 percent without destroying the capacity for molecular orientation. Molecularly oriented, cold-drawn, shaped articles of particular usefulness are prepared from copolymer compositions containing in the polymer molecules 60:99.9 percent acrylonitrile, 01-15 percent, advantageously 0.1-5 percent, the amide, with or withoutioine or more monomers of the class consisting of vinylidene chloride, vinyl chloride, styrene, alpha-methyl-styren e,

' methacrylonitrile, fumaronitrile, beta-c yano-acrylamide and methyl beta-cyano-acrylate, the effects of the presence of the monomers of this: class being noticeable whenthe monomer is presentin the polymer molecule in amounts of onejpercentorimore'. v

The polymerization products 'of this invention show great aflinity for the acetate, basic, acidic and vat dyesr acid; the sodium salt of (n-aminobenzoic acido-anisidene) phosgenated; the sodium salt of (2-naphthol- 6,8 disulfonic acid benzidine phenol) ethylated; dimethoxydibenzantlirone; and 1,5-di-p anisoylamino-4,S-dihydroxyanthraquinone. f 7

From the molecularly orientable copolymers of this invention fibers can'be prepared having improved dyeing properties, low shrinkage in boiling water, sometimes as low'a s 3 to 5 percent or less of the cold-drawn or stretched article, good heat resistance, and tensile strength in the order of 4 to 6 grams per denier. Moreoverythese properties make thefibers desirable in the manufacture of hosiery and for such all-purpose fabrics as used for blouses, shirts, suits, etc. i f i I This application is a continuation in part of application Serial No.'24 4',700 fi led August 31,1951 now abandoned.

What is claimed is: i p I 1. 'As' a new monomeric composition N-(2',6-dimethyl- 4-pyrirnidyl) maleamie acid.

2; A copolymer a polymerizable monomer having inaleaniic acid.

3. A copolymer acrylonitrile'and' N-(LtS-dimethylA pyrin'iidyl) maleamic 'acid.

4. A cold-drawn fiber having molecular orientation and dye susceptibility to acid dyes, said fiber comprising a copolymer of acrylonitrile and a member selected from the group consisting of the methyl and ethyl esters of N-(2,6-dimethyl-4-pyrimidyl) maleamic, acid, said copolymer having a molecular weight of atleast about 10,000 andicontaining in the polymer molecule no more than about 15% by weight of said amide.

5. A cold-drawn fiber having molecular orientation and dye susceptibility of acid dyes, said, fiber, comprising a copolymer of about 6098.9 percent by weight acrylonitrile, about 0.1 m5 percent by weight of a member selected from the group consisting-of the methyl and ethyl V esters of N-(2,6-dimethyl-4-pyrimidyll maleamic acid, and about 1 to 39.9 percent by weight of a compound selected from the class consisting of vinyl chloride, vinylidene chloride, styrene,alpha methyl-styrene, methacrylonitrile, fumaronitrile, beta-cyano-acrylamide, and me'thyl beta-cyano-acrylate.

6. A cold drawn fiber ha ving' molecular orientation and dye susceptibility to acid dyes, said fiber comprising a 1 copolymer of about 60-989 percent by weight acryloni- 'trile, about 0:1 to 5 percent by weight of a member selected from thegroup, consisting of the methyl and 13 ethyl esters of N-(2,6-dimethyl-4-pyrimidyl) maleamic acid and about 1 to 39.9 percent by Weight vinylidene chloride.

7. A cold-drawn fiber having molecular orientation and dye susceptibility to acid dyes, said fiber comprising a copolymer of about 60-989 percent by Weight acrylonitrile, about 0.1 to 5 percent by Weight of a member selected from the group consisting of the methyl and ethyl esters of N-(2,6-dimethyl-4-pyrimidyl) maleamic acid and about 1 to 39.9 percent by Weight vinyl chloride.

8. A cold-drawn fiber having molecular orientation and dye susceptibility to acid dyes, said fiber comprising a copolymer of about 60-989 percent by Weight acrylonitrile, about 0.1 to 5 percent by Weight of a member selected from the group consisting of the methyl and ethyl esters of N-(2,6-dimethyl-4-pyrimidyl) maleam-ic acid and about 1 to 39.9 percent by Weight styrene.

9. Monomers of the general formula:

wherein R is a member selected from the group consisting of hydrogen, methyl and ethyl, R is a member selected from the group consisting of hydrogen and methyl, and

14 Pyrm is a member selected from the group consisting of 4-amino pyrimidine, 4-amino-dilower alkyl pyrimidine and 4-amino-trilower alkyl pyrimidine radicals.

l0. N-(2,6dimethyl-4-pyrimidyl) maleamic acid.

11. Methyl-N-(2,6-dimethyl-4pyri1r1idyl) maleamate.

l2. Ethyl N-(2,6-dimethyl-4pyrimidy1) maleamate.

13. The homopolymer of the monomeric material of claim 9.

14. A copolymer of the monomeric material of claim 9 and acrylonitrile.

15. A polymeric material comprising the copolymer of claim 14 and a member selected from the group consisting of vinyl chloride, vinylidene chloride, styrene, alphamethyl-styrene, methacrylonitrile, fumaronitrile, betacyano-acrylamide, and methyl beta-cyano-acrylate.

References Cited in the file of this patent UNITED STATES PATENTS 2,643,990 Ham June 30, 1953 2,687,400 DAlelio Aug. 24, 1954- 2,687,401 DA-lelio Aug. 24, 1954 2,759,908 DAlelio Aug. 21, 1956 

9. MONOMERS OF THE GENERAL FORMULA: 